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Routines |
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Used by the routine at HandlerChasingNastie.
Updates the sprite ID of an actor so that it faces the way it is moving and flips its animation frame. Bit 1 of the sprite ID is set when the X velocity is positive, and bit 0 of the sprite ID is flipped.
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| FaceDirection | A4C3 | LD A,(IX+$06) | Fetch the X velocity of the actor. | |||||
| A4C6 | RLCA | Rotate the X velocity left twice, so that the direction is in bit 1. | ||||||
| A4C7 | RLCA | |||||||
| A4C8 | AND %00000010 | Keep only the direction bit (bit 1). | ||||||
| A4CA | LD C,A | Stash the direction bit in C. | ||||||
| A4CB | LD A,(IX+$00) | Fetch the sprite ID of the actor. | ||||||
| A4CE | AND %11111101 | Keep only bits 0 and 2-7. | ||||||
| A4D0 | OR C | Merge in the direction bit. | ||||||
| A4D1 | XOR %00000011 | Flip bits 0 and 1. | ||||||
| A4D3 | LD (IX+$00),A | Set the new sprite ID of the actor. | ||||||
| A4D6 | RET | Return. | ||||||
| Prev: A4B3 | Up: Map | Next: A4D7 |